Division is the easiest form of vegetative propagation. It involves digging up and severing a portion of the root system of a plant, and replanting it. Depending on the plant species and age, one to twenty divisions may be made from one plant. In running plants, such as the mints, partridgeberry, gotu kola, jiaogulan (Gynostemma pentaphyllum), Mondarda spp., and Arnica chamissonis, one digs up the runners (stolons and rhizomes) and plants them in a new site or container. In clumping plants, such as elecampagne, valerian, Echinacea spp., motherwort, meadowsweet, boneset, comfrey, and culver’s root, one can thrust a shovel into the center of the clump and pry free the divisionling. I generally don’t have the heart for this method and prefer digging up the whole plant and getting a good look at its root system. I then divide the roots with a garden knife (hori-hori), shovel or pruners and replant each section in it’s new garden spot. Each section contains either buds (when the plant is dormant) or leaves and shoots if the plant is actively growing and green. Take care to plant your divisionlings with the buds pointing up.
In the two images above, a clump of calamus (Acorus calamus) is divided. The image on the bottom shows three pieces that are ready to be transplanted to a new home in the garden.
Most people divide plants in the fall or spring when the plant is dormant and the temperatures are not too cold. I prefer to make divisions in the fall as there is generally less garden work than the springtime, and the roots may also grow when the plant is dormant. With my nursery, I have planted small roots from division in the fall and come spring, peeked into the pot and witnessed the growth of a larger root system, all taking place in the absence of photosynthesis! Early spring is also a fine time to divide plants. If you have a leafy active plant, cut back some of the growth as the inevitable damage to the root system will stress the plant with more leaves transpiring and losing moisture. Water in your divisionlings; seaweed tea will encourage root growth, which will increase their survival. Depending on the season, species, size of division, expertise, loving care in the transition to plant independence (watering, soil, etc.) you might have 70-100% survival.
In the four images below, a clump of meadowsweet is dug up, and pulled apart into smaller pieces which are then ready for transplanting in the garden (or in our case, into nursery pots).
We replant our divisionlings in pots with our nursery. Consider hosting or attending a spring seed/plant swap; its a great way to get to know other plant folks, learn about new useful plants, and increase variety in the garden without purchasing plants.
This article is an excerpt from a larger article on plant propagation.